1. Field of the Invention
The present invention relates to a method of forming a sampled grating and a method of producing a laser diode.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2009-53271 (Patent Literature 1) describes a method of producing a distributed feedback laser diode using a nano-imprint technique. In this method, a pattern of a diffraction grating is formed in a semiconductor layer by the nano-imprint technique. In addition, Nonpatent Literature 1 (V. Jayaraman, et. al., “Widely tunable continuous-wave InGaAsP/InP sampled grating lasers”, Electronics letters, Vol. 30, No. 18, pp. 1492-1494, (Sep. 1, 1994)) describes a distributed feedback laser diode including a sampled grating (SG).